Study on Warm Forging Prosess of 45 Steel Asymmetric Gear

International Conference on Materials Sciences and Nanomaterials

材料科学;物理学

Qi, Yushi^1 ; Du, Zhiming^1 ; Sun, Hongsheng^1 ; Chen, Lihua^2 ; Wang, Changshun^2

School of Material Science and Engineering, Harbin Institute of Technology, Harbin

150001, China^1

Technology Center, Beijing North Vehicle Group Corporation, Beijing

100072, China^2

关键词: Asymmetric gear;    Coarse grain size;    Complex structure;    Forming experiments;    Forming parameters;    Friction coefficients;    Microstructure analysis;    Mold temperatures;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/230/1/012039/pdf
DOI  :  10.1088/1757-899X/230/1/012039

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Asymmetric gear has complex structure, so using plastic forming technology to process the gear has problems of large forming load, short die life, bad tooth filling, and so on. To solve these problems, this paper presents a radial warm extrusion process of asymmetric gear to reduce the forming load and improve the filling in the toothed corner portion. Using the new mold and No. 45 steel to conducting forming experiments under the optimal forming parameters: billet temperature is 800°C, mold temperature is 250°C, the forming speed is 30mm/s, and the friction coefficient is 0.15, we can obtain the complete asymmetric gear with better surface and tooth filling. Asymmetric gears' microstructure analysis and mechanical testing showed that the small grain evenly distributed in the region near the addendum circle with high strength; the area near the central portion of the gear had a coarse grain size, uneven distribution and low strength. Significant metal flow lines at the corner part of the gear indicated that a large number of late-forming metal flowed into the tooth cavity filling the corner portion.